Gene/Protein Disease Symptom Drug Enzyme Compound
Pivot Concepts:   Target Concepts:
Query: EC:3.5.4.4 (adenosine deaminase)
 5,136 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

The adenosine deaminase-binding protein has previously been localized to the cell surface of human fibroblasts (Andy, R. J., and Kornfeld, R. (1982) J. Biol. Chem. 257, 7922-7925). In this study we examine the biosynthesis of binding protein in human fibroblasts, human hepatoma HepG2 cells, and a human kidney tumor cell line. Binding protein immunoprecipitated from radioiodinated detergent-extracted fibroblast membranes has a molecular weight of 120,000 when analyzed by sodium dodecyl sulfate-polyacrylamide gel electrophoresis. An additional band of Mr 100,000 is also present which we believe is a result of proteolysis of the 120,000 band. Purified soluble kidney binding protein has an Mr of 112,000. Binding protein from fibroblasts pulse-labeled with [35S]methionine for 15 min migrates as a 110-kDa band on sodium dodecyl sulfate-polyacrylamide gels. Within 30-60 min of chase, the intensity of the 110-kDa band is diminished, and a 120-kDa band has appeared. Binding protein reaches the cell surface of fibroblasts within 30-60 min of chase. The same results are obtained with the other cell lines studied. Thus, binding protein is initially synthesized as a precursor of 110 kDa which chases into a 120-kDa mature form. The shift of 10 kDa is probably due to processing of its oligosaccharide chains since soluble kidney-binding protein contains 7-9 complex N-linked chains. Upon endoglycosidase H treatment, the 110,000 precursor shifts to a Mr of 89,000 while the 120,000 mature band shifts to 115,000, consistent with the presence of 7-9 high mannose chains on the precursor and 1-2 high mannose chains on the mature form. These results and the presence of complex N-linked chains on binding protein were confirmed by lectin affinity chromatography of glycopeptides derived from [2-3H]mannose-labeled binding protein. Analysis of [6-3H]glucosamine-labeled binding protein indicates the presence of 1 sialic acid residue per chain.
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PMID:Biosynthesis of the adenosine deaminase-binding protein in human fibroblasts and hepatoma cells. 614 21

A large collection of cultured human tumor cell lines was characterized for the phenotypes of 16 polymorphic enzyme loci: ACP1, ADA, AK1, ESD, FUCA, GLO1, GOT2, G6PD, ME2, PEPA, PEPB, PEPC, PEPD, PGD, PGM1, and PGM3 primarily to detect and monitor against cell line contamination. Among 100 highly characterized cell lines, 59 lines from different patients and 6 pairs of lines (each pair from the same patient's tumor) had unique phenotype combinations and were therefore presumed to be authentic, uncontaminated cell lines. Besides these 71 lines, the remaining 29 lines consisted of several small groups of two to three lines, each group having a different combination and being among the more frequent in the normal population. The 29 lines, therefore, were not suspected to be contaminants. Among unusual findings were the ME2 1 plus 2 phenotype determined for two bladder tumor lines, a G6PD A phenotype found in a line of Caucasian origin determined not to be a HeLa contaminant, and asymmetrical heterozygous phenotypes in several lines. Except for kidney tumor lines, there was no correlation of adenosine deaminase tissue isoenzymes between tumor lines and normal tissues of origin. For several enzymes significant deviations were found in proportions of the phenotypes observed in Caucasian cell lines from expected proportions on the basis of normal population data, indicating possible natural selection among these lines in tissue culture or among the patients of origin.
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PMID:Distinction of seventy-one cultured human tumor cell lines by polymorphic enzyme analysis. 693 74